Charlton Heston is a personal hero of mine, but he certainly did not come out of the original smelling like a rose.
He has been one of my favorite actors since I was a kid, I loved those cheesy sci-fi movies like Soylant Green that my dad took me to back then.
The original Planet 1968 wasnt bad, it had a good theme, it had good actors, it had some good lines, it had thought provoking sci-fi imagination themes like :"Ape was made in God's image unlike the destructive Animal Man " was a great one, and the shocker visual of him on the beach reacting to the Liberty Statue is a classic. The following sequels were all crap.
But heck, I was a kid in the 1970s and in NYC around 1974 I went to see an all day showing of all five Planet movies in a row. Those were the 1970s 'Creature Feature/Chiller theater/Fright Night" days in NYC, a great time to be a kid.